Revert of Use the new java_cpp_enum rule in content. (patchset #8 id:140001 of https...

Revert of Use the new java_cpp_enum rule in content. (patchset #8 id:140001 of https://codereview.chromium.org/615893003/)

Reason for revert:
Fails to compile on several bots:

https://chromegw.corp.google.com/i/clank.tot/builders/clang-clankium-tot-builder/builds/56800/steps/compile/logs/stdio

First error:
FAILED: cd ../../clank/native/framework; python <snip ...>
../../../clank/java/apps/chrome/src/com/google/android/apps/chrome/webapps/FullScreenActivityTab.java:28: error: cannot find symbol
import org.chromium.content.common.TopControlsState;
                                  ^
  symbol:   class TopControlsState
  location: package org.chromium.content.common

Original issue's description:
> Use the new java_cpp_enum rule in content.
>
> This moves most of the generated Java enums under content/ to use the
> java_cpp_enum rule removing the need for keeping the enums in
> separate list files and the need for the .template files.
>
> BUG=405532, 351558
>
> Committed: https://crrev.com/7d5f0a581ba2f0e79b09ecbf6127ad453a861a96
> Cr-Commit-Position: refs/heads/master@{#297789}

TBR=jam@chromium.org,yfriedman@chromium.org,scottmg@chromium.org,jdduke@chromium.org,brettw@chromium.org,mkosiba@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=405532, 351558

Review URL: https://codereview.chromium.org/625543002

Cr-Commit-Position: refs/heads/master@{#297793}